I have used it all over my house. Good stuff.
I used it on all walls and ceiling in one room and it can get quite warm compared to the other living room. Holds the heat well too.
Only downside is that it is tough to clean the walls, think sand in paint!
However, I now only use it on ceilings and I would say it makes a difference.

Whether this stuff works or not, the important thing is does it make the walls 'gritty'?

If it does, then my advice would be don't touch it with a bargepole. There is nothing worse than walls and/or ceilings that have been painted with paint that looks and feels gritty. You may love it and it may save you a few pennies a year in heating costs, but could costs you a lot more if you sell it. The number of times I have been asked if it is possible to remove textured coatings

Surely a company wouldn't have developed a product like this for NASA and NOT have a worldwide patent on it. This makes me think that the Thermilate is a cheap copy, maybe with polystyrene beads used instead of a vaccuum.

There is at least more information on the Insuladd site than the Thermalite one, also this - "Tech Traders Inc. has seen a number of companies spring up that claim to have NASA technology. These companies are simply adding common microsphere products to paints or selling them as "insulating additives for paint". Tech Traders Inc. recommends that consumers look closely for real and verifiable 3rd party laboratory testing prior to purchasing any product that claims to be an insulating paint or insulating additive."

I had gone through the post. Thermilate Insulating paint additive and environmental Issue. I have seen this product applied to concrete wall, the small granules make th epaint slightly matt in texture, The funny thing is if you put your hand on the wall it feels warm. I can't say it is totally different from normal paints, but I feel the difference on it when compared with the normal paint. Please produce some more attached files for the detailed view of the topic.